package com.example.lotterysystem.service.mq;

import cn.hutool.core.date.DateUtil;
import cn.hutool.poi.excel.ExcelPicUtil;
import com.example.lotterysystem.common.exception.ServiceException;
import com.example.lotterysystem.common.utils.JacksonUtil;
import com.example.lotterysystem.common.utils.MailUtil;
import com.example.lotterysystem.common.utils.SMSUtil;
import com.example.lotterysystem.controller.param.DrawPrizeParam;
import com.example.lotterysystem.dao.dataobject.ActivityPrizeDO;
import com.example.lotterysystem.dao.dataobject.WinningRecordDO;
import com.example.lotterysystem.dao.mapper.ActivityPrizeMapper;
import com.example.lotterysystem.dao.mapper.WinningRecordMapper;
import com.example.lotterysystem.service.DrawPrizeService;
import com.example.lotterysystem.service.activitystatus.ActivityStatusManger;
import com.example.lotterysystem.service.dto.ConvertActivityStatusDTO;
import com.example.lotterysystem.service.enums.ActivityPrizeStatusEnum;
import com.example.lotterysystem.service.enums.ActivityPrizeTiersEnum;
import com.example.lotterysystem.service.enums.ActivityStatusEnum;
import com.example.lotterysystem.service.enums.ActivityUserStatusEnum;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;

import java.awt.*;
import java.rmi.ServerException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import static com.example.lotterysystem.common.config.DirectRabbitConfig.QUEUE_NAME;

@Component
@RabbitListener(queues = QUEUE_NAME)
public class MqReceiver {
    public static final Logger logger = LoggerFactory.getLogger(MqReceiver.class);

    @Autowired
    private ActivityStatusManger activityStatusManager;

    @Autowired
    private SMSUtil smsUtil;

    @Autowired
    private MailUtil mailUtil;

    @Autowired
    private DrawPrizeService drawPrizeService;

    @Autowired
    private ActivityStatusManger activityStatusManger;

    @Autowired
    private ThreadPoolTaskExecutor threadPoolTaskExecutor;

    @Autowired
    private ActivityPrizeMapper activityPrizeMapper;

    @Autowired
    private WinningRecordMapper winningRecordMapper;

    @RabbitHandler
    public void process(Map<String, String> message) throws Exception {
        // 成功接受队列中的消息
        logger.info("MQ 成功接收到消息，message: {}",
                JacksonUtil.writeValueAsString(message));
        String paramString = message.get("messageData");
        DrawPrizeParam param = JacksonUtil.readValue(paramString, DrawPrizeParam.class);

        // 处理抽奖的流程
        try {
//            if (true) {
//                return;
//            }

            // 校验抽奖请求是否有效
            if (!drawPrizeService.checkDrawPrizeParam(param)) {
                return;
            };

            // 执行扭转处理（加入设计模式）
            statusConvert(param);

            // 保存中奖者名单
            List<WinningRecordDO> winningRecordDOList = drawPrizeService.saveWinnerRecords(param);

            // 通知中奖者（邮箱、短信）
            // 抽奖之后的后续流程，异步（并发）处理
            syncExecute(winningRecordDOList);


        } catch (ServiceException e) {
            logger.error("处理 MQ 消息异常！{}:{}", e.getCode(), e.getMessage(), e);
            // 需要保证事务一致性（回滚）
            rollback(param);

            // 抛出异常:消息重试（解决异常：代码bug、网络问题、服务问题）
            throw e;
        } catch (Exception e) {
            logger.error("处理 MQ 消息异常！", e);
            // 需要保证事务一致性（回滚）
            rollback(param);

            // 抛出异常
            throw e;
        }
    }

    /**
     * 处理抽奖异常的回滚行为：恢复处理请求之前的库表状态
     * @param param
     */
    private void rollback(DrawPrizeParam param) {

        // 1、回滚状态：活动、奖品、人员
        // 状态是否需要回滚
        if (!statusNeedRollback(param)) {
            // 不需要: return
            return;
        }

        // 需要回滚
        rollbackStatus(param);
        
        // 2、回滚中奖者名单
        // 是否需要回滚
        if (!winnerNeedRollback(param)) {
            // 不需要: return
            return;
        }
        // 需要回滚
        rollbackWinner(param);
    }

    private boolean statusNeedRollback(DrawPrizeParam param) {
        // 正常思路： 判断活动 + 奖品 + 人员表 的相关状态是否已经扭转
        // 但扭转状态时，保证了事务的一致性，要么都扭转，要么都没扭转
        // 同时，人员表 和 活动表 的状态都是根据奖品表的状态来决定是否扭转的
        // 故，只需判断 奖品表 的状态是否已经扭转

        ActivityPrizeDO activityPrizeDO =
                activityPrizeMapper.selectByAPId(param.getActivityId(), param.getPrizeId());
        // 已经扭转了，需要回滚
        return activityPrizeDO.getStatus()
                .equalsIgnoreCase(ActivityPrizeStatusEnum.COMPLETED.name());

    }

    private void rollbackWinner(DrawPrizeParam param) {
        drawPrizeService.deleteRecords(param.getActivityId(), param.getPrizeId());
    }

    private boolean winnerNeedRollback(DrawPrizeParam param) {
        // 判断活动中的奖品是否存在中奖者
        int count = winningRecordMapper.countByAPId(param.getActivityId(), param.getPrizeId());
        return count > 0;
    }

    /**
     * 恢复相关状态
     * @param param
     */
    private void rollbackStatus(DrawPrizeParam param) {
        // 涉及状态的恢复，使用 ActivityStatusManger
        ConvertActivityStatusDTO convertActivityStatusDTO = new ConvertActivityStatusDTO();
        convertActivityStatusDTO.setActivityId(param.getActivityId());
        convertActivityStatusDTO.setTargetActivityStatus(ActivityStatusEnum.RUNNING);
        convertActivityStatusDTO.setPrizeId(param.getPrizeId());
        convertActivityStatusDTO.setTargetPrizeStatus(ActivityPrizeStatusEnum.INIT);
        convertActivityStatusDTO.setUserIds(
                param.getWinnerList().stream()
                        .map(DrawPrizeParam.Winner::getUserId)
                        .collect(Collectors.toList())
        );
        convertActivityStatusDTO.setTargetUserStatus(ActivityUserStatusEnum.INIT);
        activityStatusManager.rollbackHandlerEvent(convertActivityStatusDTO);


    }

    /**
     * 并发处理抽奖后续流程
     * @param winningRecordDOList
     */
    private void syncExecute(List<WinningRecordDO> winningRecordDOList) {
        // 通过线程池 threadPoolTaskExecutor
        // 短信通知
        threadPoolTaskExecutor.execute(() -> sendMessage(winningRecordDOList));
        // 邮件通知
        threadPoolTaskExecutor.execute(() -> sendEmail(winningRecordDOList));
    }

    /**
     * 发邮件
     * @param winningRecordDOList
     */
    private void sendEmail(List<WinningRecordDO> winningRecordDOList) {
        if (CollectionUtils.isEmpty(winningRecordDOList)) {
            logger.info("中奖者名单为空，不发送短信！");
            return;
        }
        for (WinningRecordDO winningRecordDO : winningRecordDOList) {
            // Hi, xxx。恭喜你在 xx 活动中获得 xx 等奖： xxx。获奖时间为 xx:xx:xx,请尽快领取您的奖励
            String context = "Hi. " + winningRecordDO.getWinnerName() + "。恭喜你在"
                    + winningRecordDO.getActivityName() + "活动中获得"
                    + ActivityPrizeTiersEnum.forName(winningRecordDO.getPrizeTier()).getMessage()
                    + ": " + winningRecordDO.getPrizeName() + "。获奖时间为"
                    + DateUtil.formatTime(winningRecordDO.getWinningTime()) + ",请尽快领取您的奖励!";
            mailUtil.sendSampleMail(winningRecordDO.getWinnerEmail(),
                    "中奖通知",
                    context);
        }
    }

    /**
     * 发短信
     * @param winningRecordDOList
     */
    private void sendMessage(List<WinningRecordDO> winningRecordDOList) {
        if (CollectionUtils.isEmpty(winningRecordDOList)) {
            logger.info("中奖者名单为空，不发送短信！");
            return;
        }
        for (WinningRecordDO winningRecordDO : winningRecordDOList) {
            Map<String, String> map = new HashMap<>();
            map.put("name", winningRecordDO.getWinnerName());
            map.put("activityName", winningRecordDO.getActivityName());
            map.put("prizeTier", ActivityPrizeTiersEnum.forName(winningRecordDO.getPrizeTier()).getMessage());
            map.put("prizeName", winningRecordDO.getPrizeName());
            map.put("winningTime", DateUtil.formatTime(winningRecordDO.getWinningTime()));
            smsUtil.sendMessage("SMS_474990182",
                    winningRecordDO.getWinnerPhoneNumber().getValue(),
                    JacksonUtil.writeValueAsString(map));
        }
    }
    /**
     * 状态扭转
     * @param param
     */
    private void statusConvert(DrawPrizeParam param) {
        ConvertActivityStatusDTO convertActivityStatusDTO = new ConvertActivityStatusDTO();
        convertActivityStatusDTO.setActivityId(param.getActivityId());
        convertActivityStatusDTO.setTargetActivityStatus(ActivityStatusEnum.COMPLETED);
        convertActivityStatusDTO.setPrizeId(param.getPrizeId());
        convertActivityStatusDTO.setTargetPrizeStatus(ActivityPrizeStatusEnum.COMPLETED);
        convertActivityStatusDTO.setUserIds(
                param.getWinnerList().stream()
                        .map(DrawPrizeParam.Winner::getUserId)
                        .collect(Collectors.toList())
        );
        convertActivityStatusDTO.setTargetUserStatus(ActivityUserStatusEnum.COMPLETED);
        activityStatusManger.handlerEvent(convertActivityStatusDTO);
    }

        // 问题：
        // 1、活动状态扭转对顺序有依赖性，导致代码维护性差
        // 2、状态转条件可能会扩展，当前写法的扩展性和维护性较差
        // 3、代码的灵活性、扩展性、维护性极差
        // 解决方案：设计模式（责任链设计模式、策略模式）

        // 活动：RUNNING -> COMPLETED 需在全部奖品抽完之后再改变状态
        // 奖品：INIT -> COMPLETED
        // 人员列表：INIT -> COMPLETED

        // 1. 扭转奖品状态
        // 查询活动关联的奖品信息
        // 判断当前状态是否是 COMPLETED，如果不是，则要扭转


        // 2. 扭转人员状态
        // 判断当前状态是否是 COMPLETED，如果不是，则要扭转

        // 3. 扭转活动状态（需在扭转奖品状态之后完成）
        // 判断当前状态，确保已经在全部奖品抽完之后，同时状态是 COMPLETED，则要扭转

}
